George Sauer Jr., the iconoclastic wide receiver who was a key member of the Jets’ Super Bowl III championship team that upset the heavily favored Baltimore Colts, died Tuesday in Westerville, Ohio. He was 69.

His sister, Dana Keifer, told the New York Times the cause of death was congestive heart failure. Sauer, who retired from the game following the 1970 season at the age of 27 after becoming disillusioned with the life of a football player, was also afflicted with Alzheimer’s disease, his sister said.

Sauer played for the Jets in both the AFL and NFL from 1965-70 and was named an AFL All-Star four times.

He appeared in 84 games, catching 309 passes for 4,965 yards and 28 touchdowns.

In the team’s 16-7 upset of the Colts, Sauer caught eight passes from Joe Namath for 138 yards after the quarterback’s primary target, Don Maynard, was hobbled by a hamstring pull.

An outstanding receiver at the University of Texas, the 6-foot-2, 195-pound Sauer was the son of George Sauer Sr., a college coach and NFL executive. The younger Sauer was enrolled in the university’s pre-med program, but gave up his dream of becoming a doctor because he found it difficult to balance his studies and football.

He left school with a year of eligibility to sign with the Jets, where his father was the director of player personnel.

After leaving the Jets, Sauer played for the New York Stars and Charlotte Hornets of the World Football League during the 1974 season.